Related Experiment Videos
Mutagens in extracts of human gastric mucosa
Abstract:
Extracts of mucosa from 53 stomachs were tested for mutagenicity with the use of Salmonella typhimurium strains TA98 and TA100. Mutagenic activity was observed in nonneoplastic mucosa from seven stomachs with S. typhimurium strain TA98 without the S-. mix (a rat liver microsomal enzyme preparation) and in three stomachs with TA100 without S-. mix. All of the TA98 mutagenic samples were derived from stomachs showing evidence of intestinal metaplasia. The exception was an extract of corpus mucosa that was mutagenic with strain TA100. "Transnitrosoase" activity was found in 12 of 53 samples, all of which showed TA98 mutagenicity. Whether the presence of mutagens and transnitrosoase activity causes intestinal metaplasia or results from it is uncertain.
Insights
Stomach mucosal extracts showed mutagenic activity in some non-cancerous tissues, particularly those with intestinal metaplasia. Further research is needed to understand the relationship between mutagens, transnitrosoase activity, and intestinal metaplasia.
Area of Science:
- Gastroenterology
- Toxicology
- Oncology
Background:
- Gastric mucosal changes, including intestinal metaplasia, are associated with an increased risk of gastric cancer.
- The presence of mutagens in gastric tissue may play a role in the development of these changes.
Purpose of the Study:
- To investigate the mutagenicity of gastric mucosal extracts.
- To explore the association between mutagenic activity, transnitrosoase activity, and intestinal metaplasia in the stomach.
Main Methods:
- Gastric mucosal samples from 53 individuals were analyzed.
- Mutagenicity testing was performed using Salmonella typhimurium strains TA98 and TA100, with and without a rat liver microsomal enzyme preparation (S9 mix).
- Transnitrosoase activity was also assessed.
Main Results:
- Mutagenic activity was detected in non-neoplastic mucosa from seven stomachs using Salmonella typhimurium strain TA98 without S9 mix.
- Three stomachs showed mutagenicity with strain TA100 without S9 mix.
- All TA98 mutagenic samples originated from stomachs with intestinal metaplasia.
- Transnitrosoase activity was found in 12 samples, all exhibiting TA98 mutagenicity.
Conclusions:
- Mutagens are present in some non-neoplastic gastric mucosa, particularly in cases of intestinal metaplasia.
- A correlation exists between TA98 mutagenicity, transnitrosoase activity, and intestinal metaplasia.
- The causal relationship between mutagens, transnitrosoase activity, and intestinal metaplasia remains to be elucidated.